“…The instrumentation developed features laser light sources coupled into trapping mass spectrometers that are used to mass-select the ion population of interest and to store the selected ion population for extended periods of time. Several types of mass spectrometers have been employed, including 3-D Paul-type quadrupole ion traps (QIT) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17], Fourier transform ion cyclotron resonance mass spectrometers (FT-ICR-MS) [18][19][20][21][22][23], and linear radiofrequency ion traps (LIT) [24]. Detection of integrated gas-phase fluorescence has been accomplished using high-sensitivity photomultiplier tubes [5-7, 9-11, 13-17, 21-24] or avalanche photodiodes [18,19,25], while dispersed fluorescence has been measured using spectrographs with charge-coupled device (CCD) detectors [1-4, 8, 12, 22].…”